The Spurs boss said that the Frenchman has gradually lost his notoriously calm demeanour in recent years.
"He used to be known as The Professor, sitting on the bench like a chess master," Redknapp said. "All the other idiots are jumping up and down, shouting and screaming and Arsene sits there studying every move on the pitch.
"Suddenly they start losing and he's one of the biggest nutters of all. He's jumping around more than anyone now. That's how it gets you, we all do it. It's pressure."
Wenger became involved in a dispute at the weekend over a successful eleventh hour penalty awarded to Liverpool.
Redknapp added: "What was he going through when Liverpool got that free-kick on the edge of the box? I was thinking 'my God I've been there so many times'. It was the last minute of the game and it's the worst feeling in the world waiting for that free-kick. What he must have gone through on Sunday mustn't be good for your health."
Tottenham v Arsenal kicks off tonight at 19.45.